Conventionally, devices such as a drug dispensing apparatus and a drug filling apparatus have a drug feeder for dispensing tablets contained therein one by one to a predetermined position. Some drug feeders employ a rotor provided with a one stage pocket region as described in Patent Documents 1 and 2 specified below and others employ a rotor provided with an upper and lower stage pocket region as described in Patent Documents 3, 4, 5, and 6 specified below. In any of them, each drug feeder is roughly composed of a drug cassette for accommodating a large number of tablets, a support base where the drug cassette is to be mounted, and a separating member, as disclosed in Patent Documents described below.
A drug cassette is provided with a storage part having a drug storage space for accommodating a large number of tablets with a rotor housed in the storage part. The rotor has drug storage grooves on the outer peripheral face of the rotor, so as to form a plurality of pockets in spaces between the grooves and an inner wall of the storage part. The pockets have a function of flowing in and holding the tablets contained in the storage part. The drug storage grooves each are opened at upper and lower sides. The pockets each are a space formed by the groove and the inner wall of the storage part, which closes an opening of the groove, and are opened at upper and lower sides.
The rotor has a rotating shaft on which a rotor gear is mounted. Further, the storage part has a drug discharging outlet at a position allowing communication with the drug storage groove disposed on the outer peripheral face of the rotor.
The separating member is of a plate shape or a comb-like shape and is attached to an upper part of the drug discharging outlet.
In a drug feeder provided with a rotor having a one stage pocket region as disclosed in Patent Documents 1 and 2, as shown in FIGS. 20A to E, a separating member 100 is located further above a pocket region 102 having drug storage grooves 101.
Specifically, as shown in FIGS. 20A to E, a row of the drug storage grooves 101 is arranged above a drug discharging outlet 103 and, moreover, above the row the separating member 100 is arranged.
The support base houses a motor such as a geared motor, a driving gear being mounted on a rotating shaft of the motor.
Upon driving of the motor housed in the support base, a rotational force is transferred from the driving gear to the rotor gear, thereby rotating a rotor 105 in a direction of an arrow as shown in FIGS. 20A to E, and further rotating the drug storage grooves 101 formed on the outer peripheral face of the rotor 105. The rotation of the rotor 105 agitates the tablets in the storage part, so that the tablets enter each pocket 108 through an opening 106 of the upper side of the pocket 108.
Further rotation of the rotor 105 allows the pockets 108 to reach the drug discharging outlet 103 in rotation, so that the tablets held in the pockets 108 are sequentially discharged through the drug discharging outlet 103, as shown in FIG. 20B.
Though each of the pockets 108 is a space opened at the upper and lower sides as described above, the opening 106 of the upper side of the pocket 108 is closed by the separating member 100 when the pocket 108 reaches the drug discharging outlet 103 since the separating member 100 is located above the drug discharging outlet 103 and further above the drug storage grooves 101.
The tablets held in each of the pockets 108 are sequentially discharged through the drug discharging outlet 103 when the relevant pocket 108 reaches the drug discharging outlet 103, and whereby the relevant pocket 108 becomes empty, but no tablet newly drops in the pocket 108 near the drug discharging outlet 103 because the opening 106 of the upper side of the pocket 108 is closed by the separating member 100 at the relevant position.
Consequently, only a specific number of tablets held in the pocket beforehand are discharged through the drug discharging outlet 103. As explained in an example shown in FIGS. 20A to E, only one tablet A having been held in the pocket 108 is discharged through the drug discharging outlet 103, while a tablet C right above the tablet A remains on the separating member 100.
Patent Documents 3, 4, 5, and 6 each disclose a drug feeder provided with a rotor having the upper and lower stage pocket region. In a case of the use of the rotor having the upper and lower stage structure, a separating member is disposed between the lower pocket region and the upper pocket region, thereby preventing more than a predetermined number of tablets from entering the lower pockets.
Patent Documents 3 and 4 each disclose an embodiment in which the upper pockets each have an opening with inclination so as to present concave and convex shapes.
The concaves and convexes of the rotor disclosed in Patent Documents 3 and 4 are positioned above the separating member so as not to be brought into contact with the separating member.
Patent Document 5 discloses a configuration in which the rotor has a block part on its side face, above which a projection is provided.
The projection disclosed in Patent Document 5 is located above the separating member so as not to be brought into contact with the separating member.